From: Krzysztof Kozlowski <krzk@kernel.org>
To: "Viresh Kumar" <viresh.kumar@linaro.org>,
linux-kernel@vger.kernel.org,
"Michael S. Tsirkin" <mst@redhat.com>,
"Jason Wang" <jasowang@redhat.com>,
"Xuan Zhuo" <xuanzhuo@linux.alibaba.com>,
"Eugenio Pérez" <eperezma@redhat.com>
Cc: "Arnd Bergmann" <arnd@kernel.org>,
"Vincent Guittot" <vincent.guittot@linaro.org>,
"Alex Bennée" <alex.bennee@linaro.org>,
"Bill Mills" <bill.mills@linaro.org>,
"Rob Herring" <robh@kernel.org>,
"Saravana Kannan" <saravanak@google.com>,
devicetree@vger.kernel.org, virtualization@lists.linux.dev,
"Sudeep Holla" <sudeep.holla@arm.com>,
"Bertrand Marquis" <bertrand.marquis@arm.com>,
"Edgar E . Iglesias" <edgar.iglesias@amd.com>,
"Arnaud Pouliquen" <arnaud.pouliquen@foss.st.com>,
"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
"Conor Dooley" <conor+dt@kernel.org>
Subject: Re: [RFC PATCH 6/6] virtio-msg: Add support for loopback bus
Date: Wed, 30 Jul 2025 11:49:14 +0200 [thread overview]
Message-ID: <1ba0e803-cbca-43d0-be9d-79fef4e54201@kernel.org> (raw)
In-Reply-To: <622460b11118be66d5ec380b3d5771be77fc1e91.1753865268.git.viresh.kumar@linaro.org>
On 30/07/2025 11:29, Viresh Kumar wrote:
> Add a loopback bus implementation for the virtio-msg transport.
>
> This bus simulates a backend that echoes messages to itself, allowing
> testing and development of virtio-msg without requiring an actual remote
> backend or transport hardware.
>
> The loopback bus requires a reserved memory region for its operation.
> All DMA-coherent and streaming DMA allocations are restricted to this
> region, enabling safe mapping into user space and helping validate the
> memory-sharing model.
>
> The reserved-memory region must be named "vmsglb" in the device tree.
No, because I can name regions how I wish. You cannot add undocumented
ABI and claim in commit msg, that the commit msg is the ABI.
Either you have ABI documented or you cannot rely on implicit ABI, thus
remove above restriction.
This is really poor choice to add such hidden ABI and it already broke
several users in the past.
Best regards,
Krzysztof
next prev parent reply other threads:[~2025-07-30 9:49 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-30 9:29 [RFC PATCH 0/6] virtio: Add support for Virtio message transport Viresh Kumar
2025-07-30 9:29 ` [RFC PATCH 1/6] of: reserved-memory: Add reserved_mem_device_init() Viresh Kumar
2025-07-30 9:29 ` [RFC PATCH 2/6] of: reserved-memory: Add of_reserved_mem_lookup_by_name Viresh Kumar
2025-07-30 9:46 ` Krzysztof Kozlowski
2025-07-30 10:57 ` Viresh Kumar
2025-07-30 11:24 ` Krzysztof Kozlowski
2025-08-01 6:02 ` Viresh Kumar
2025-07-30 9:29 ` [RFC PATCH 3/6] virtio: Add support for virtio-msg transport Viresh Kumar
2025-07-30 9:29 ` [RFC PATCH 4/6] virtio-msg: Add optional userspace interface for message I/O Viresh Kumar
2025-07-30 9:29 ` [RFC PATCH 5/6] virtio-msg: Add support for FF-A (Firmware Framework for Arm) bus Viresh Kumar
2025-07-30 9:29 ` [RFC PATCH 6/6] virtio-msg: Add support for loopback bus Viresh Kumar
2025-07-30 9:49 ` Krzysztof Kozlowski [this message]
2025-07-30 13:39 ` [RFC PATCH 0/6] virtio: Add support for Virtio message transport Rob Herring
2025-08-12 9:49 ` Viresh Kumar
2025-08-12 13:28 ` Rob Herring
2025-08-13 6:28 ` Viresh Kumar
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